import java.util.Scanner;

public class SumFun {

public static void main(String[] args) {

Scanner keyboard = new Scanner(System.in);

int sum = 0;

int input;

//priming read

System.out.println("Enter non-negative to add to sum");

System.out.println("Enter a negative to exit!");

input = keyboard.nextInt();

while(input >= 0) {

sum += input; //sum = sum + input;

System.out.println("Enter non-negative to add to sum");

System.out.println("Enter a negative to exit!");

input = keyboard.nextInt();

}//end while

System.out.println("Sum is " + sum);

}//end main

}